8-tetradecenal as fragrance and flavoring substance

ABSTRACT

The invention relates to the use of (Z)-8-tetradecenal and of a mixture consisting of (Z)-8-tetradecanal and (E)-8-tetradecanal as an odorous or aromatic substance.

CROSS REFERENCE TO RELATED APPLICATION

This application is a national stage of PCT/EP02/07547 filed Jul. 6,2002 and based upon DE 101 33 541.5 filed Jul. 11, 2001 under theInternational Convention.

FIELD OF THE INVENTION

The invention relates to the use of (Z)-8-tetradecenal,(E)-8-tetradecenal or a mixture of (Z)-8- and (E)-8-tetradecenal asperfume (fragrance) or flavoring agent (flavoring).

The invention furthermore relates to a corresponding method forimparting or intensifying a citrus perfume or citrus flavor to a basecomposition, a method for modifying a perfume and flavoring compositionand also corresponding perfume or flavoring compositions themselves.

BACKGROUND TO THE INVENTION

In perfuming and flavoring practice there is generally an ongoingrequirement for synthetic perfumes and flavoring agents that can beprepared inexpensively and with constant quality, remain stable onprolonged storage, if possible also in contact with other substances,and have desired olfactory or taste characteristics. Perfumes shouldhave pleasant perfume notes of adequate intensity that are as natural aspossible and be able to have an advantageous effect on the perfume ofcosmetics or industrial consumer goods. Flavoring agents should beeasily digestible, be reminiscent of typical flavor components ofpopular foods or even identical to the latter and be able to make apositive contribution to the flavor of foods, medicaments to beadministered orally, and the like. Discovering perfume and flavoringagents that comply with these requirements has proved to be relativelylaborious and demands regular extensive research, in particular if theaim is to find interesting novel perfume notes or flavor trends.

The search for suitable perfume or flavoring agents is made moredifficult for the person skilled in the art, in particular because ofthe following factual issues:

-   The mechanisms of perfume and flavor perception are not known.-   Objective, quantitative characterization of a perfume or flavor is    not possible.-   The relationships between perfume and/or flavor perception, on the    one hand, and the chemical structure of the perfume and/or flavoring    agent, on the other hand, have not been adequately researched.-   Frequently even minor changes in the structural composition of known    perfume or flavoring agents give rise to substantial changes in the    olfactory or flavor characteristics and impair the compatibility for    the human organism.

The success of the search for suitable perfume or flavoring agentstherefore frequently depends on the intuition of the searcher.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a diagrammatic scheme for the synthesis of(Z)-8-tetradecenal, and

FIG. 2 shows a diagrammatic scheme for the synthesis of(E)-8-tetradecenal.

DETAILED DESCRIPTION

The objective on which the present invention is based is, taking intoaccount the general framework conditions described above, to indicate aperfume and flavoring agent which, in particular, is able to impart afresh citrus perfume to conventional perfume or flavor base compositionsor to modify the existing citrus perfume of such compositions in anadvantageous manner, i.e. in particular to freshen it, to make it appearjuicier and more authentic and to impart body and fullness to the entirecomposition.

The substances to be indicated should, in particular, be able to have anadvantageous influence on the sensory properties of citrus fruitcompositions, i.e. of compositions that remind the consumer of, forexample, bitter orange, lime, grapefruit, mandarin, clementine, lemon,cedral lemon, orange, kumquat or the like and/or contain citrus oils.

The substances to be indicated should offer the perfumerer or flavoringspecialist an alternative to the citrus perfumes or flavoring agentsused or described hitherto which can be widely used when composingperfumes or flavors. Specifically, in the creative process ofcomposition, a laborious process, which as a rule is carried out only byspecialists, it is not sufficient to use, in the manner of a template,an arbitrary perfume or flavoring agent to which a specific fragrance orflavor aspect has been assigned in the literature in order to obtain aperfume or flavor image that already exists in the imagination.Specifically, the fragrance or flavor characteristic of a compositioncannot be precisely predicted in the sense of an addition if only theconstituents of the composition are known, since these constituents aresubject to unforeseeable interactions in the mixture. The compatibilityof a perfume or flavoring agent with the other constituents of acomposition and the presence or lack of accompanying aspects that can bedetected by the senses and also have an effect on the overall characterof the finished composition, without them perhaps being particularlyacknowledged in the description of the fragrance of the pure substance,is therefore also important.

The invention is based on the surprising finding that, in particular(Z)-8-tetradecenal, but also to a somewhat weakened extent(E)-8-tetradecenal, as well as mixtures of (Z)-8- and (E)-8-tetradecenalare outstandingly suitable for use as perfume and flavoring agent andalso to achieve the objectives indicated above.

(Z)-8-tetradecenal has a particularly low odor threshold value of only0.009 ppb (odor threshold value in water), so that even small amounts ofthis substance give rise to a modification of a perfume or flavoring(base) composition that can be detected by the senses. It is true that,according to our own research, the odor threshold of (E)-8-tetradecenalis only at 1.24 ppb, but it is still outstandingly suitable for use inperfume and flavoring agent compositions, and specifically especially asa mixture with (more active) (Z)-8-tetradecenal.

The substances (Z)-7-tetradecenal and (Z)-9-tetradecenal, which areclosely related to (Z)-8-tetradecenal according to the invention inrespect of chemical structure and, in contrast to the latter, arecommercially available, do not have any usable sensory propertiescompared with (Z)-8-tetradecenal. In particular, their odor threshold issurprisingly approximately two orders of magnitude higher than that of(Z)-8-tetradecenal; in this context see the example further below.

The substances (Z)-8- and (E)-8-tetradecenal are already known and, inthis regard, reference is made in particular to the followingliterature:

-   1. Kováts Retention Indexes of Monounsaturated C12, C14 and C16    Alcohols, Acetates and Aldehydes Commonly Found in Lepidopteran    Pheromone Blends (Francisco de A. Marques, J. S. McElfresh,    Jocelyn G. Millar; J. Braz. Chem. Soc. (2000), 11 (6), 592-599).-   2. Gas chromatographic determination of vapour pressures of    pheromone-like compounds III. Aldehydes (Bohumir Koutek, Michal    Hoskovec, Pavlina Vrkocová, Karel Knecný, Ladislav Feltl, Jan    Vrkoc; J. Chromatogr., A (1996), 719 (2), 391-400).-   3. Mammalian Exocrine Secretions: IX. Constituents of Preorbital    Secretion of Oribi, Ourebia, ourebi (W.-P. Mo, B. V. Burger, M.    LeRoux, H. S. C. Spies; Chem. Ecol. (1995), 21(8), 1191-215).

However, the sensory properties of (Z)-8- and (E)-8-tetradecenal havenot been studied to date; the abovementioned documents relate toproblems in clarification of the structure in relation to the study ofpheromones.

Publications on the organoleptic or sensory properties of aliphaticaldehydes, to which the substances according to the invention belongafter all, also gave no indication of the special properties of(Z)-8-tetradecenal and (E)-8-tetradecenal.

Volatile components of coriander plants, which also include a number ofaliphatic aldehydes, are described in the article on “Character-impactaroma components of coriander (Coriandrum sativum I.) herb”,Cadwallader, K. R.; Surakarnkul, R.; Yang, S.-P.; Webb, T. E. FlavorChem. Ethn. Foods, [Proc. Meet. 5^(th) Chem. Cong. North Am.] (1999),Meeting Date 1997, 77-84. Editor(s): Shahidi, Fereidoon; Ho, Chi-Tang.Publisher: Kluwer Academic/Plenum Publishers, New York, N.Y. Compoundstested are indicated giving a description of the odor in a Table 1.However, a citrus-like odor is assigned to only one compound of thealkanals tested, specifically a “citrus peel” odor to the relativelyshort-chain compound (E)-4-decenal, which odor is, however, in thebackground behind a green odor in terms of intensity. The odor of(E)-2-tetradecenal, which has the same chain length as the compoundsaccording to the invention but, however, contains a double bondconjugated to the carbonyl group and, to this extent, is chemically notcomparable to the compounds according to the invention, is, on the otherhand, indicated only as “fatty, waxy, cheesy”; and the other alkanalstested also do not include a citrus odor aspect.

Subjectively quantified organoleptic properties of aldehydes aresummarised in an article on “Organoleptic properties of aliphaticaldehydes”, Boelens, Mans H.; Van Gemert, Leo J.; Perfum. Flavor.(1987), 12(5), 31-7, 40, 43. In this study, the aldehydes studied werealso assessed subjectively with regard to their citrus character and itcan be established that, in the view of the perfumerers and flavoringspecialists carrying out the study, the compound (E)-2-tetradecenal,which is already known from the literature discussed above, includes aweak citrus aspect which, however, is clearly in the background behind astrong fatty aspect. The situation is quite similar in the case of thefurther mono-unsaturated aldehydes studied and specifically especiallyin the case of the aldehydes with a non-conjugated double bond. If theseinclude a citrus aspect at all (which is not the case in the majority ofcases), this aspect is overlaid by the green, fatty and/or flowery odoraspects. A noteworthy citrus aspect was assigned only to the substancestrans-2-octenal, trans-2-decenal and trans-2-undecenal (especially indilute form), each of which contains a conjugated double bond. However,because of their deviating chain length and the conjugation of thedouble bonds, these substances are chemically no longer particularlysimilar to the compounds according to the invention, so that it was notpossible for a person skilled in the art to derive anything from theirsensory properties for the substances according to the invention. In ourown performance comparison tests, the substances according to theinvention (with non-conjugated double bond) were, moreover, clearlysuperior to the trans-2-alkenals mentioned. Furthermore, in contrast tothe said trans-2-alkenals, the substances according to the inventionimpart body and fullness to the perfume and flavor compositions. Themodifications achieved by the substances according to the inventioncould thus not be achieved by the said trans-2-alkenals.

Viewed from a slightly different angle, the present invention makesavailable a method for imparting a citrus perfume or citrus flavor to orintensifying a citrus perfume or citrus flavor of a base composition,which is characterised in that

-   (a) an amount of (Z)-8-tetradecenal, (E)-8-tetradecenal or of a    mixture of (Z)-8- and (E)-8-tetradecenal that is effective from the    sensory standpoint and-   (b) constituents of the base composition are mixed.

With this method the base composition can be initially introducedcomplete or the substance according to the invention listed under (a)can be mixed with the constituents of the base composition that havebeen initially introduced in any desired sequence.

The invention also relates to a method for modifying a perfume or flavorcomposition (that is prespecified physically or in terms of itscomposition), wherein an amount of (Z)-8-tetradecenal,(E)-8-tetradecenal or of a mixture of (Z)-8- and (E)-8-tetradecenal thatmodifies the perfume or the flavor is added to the perfume or flavorcomposition.

With this method the perfume or flavor composition to be modified can beinitially introduced complete or the substance according to theinvention can be mixed with the specified constituents of the perfume orflavor composition in any desired sequence. After what has been statedabove, it is clear that the modification is, as a rule, carried out withregard to the citrus aspect; however, it is also possible to allowcertain citrus perfume or flavor compositions to appear fresher,juicier, fuller and/or more typical by the addition of the substancesaccording to the invention, without influencing the primary citrusaspect to a noteworthy extent.

The present invention also relates to a perfume or flavor compositionthat contains an amount of (Z)-8-tetradecenal, (E)-8-tetradecenal or amixture of (Z)-8- and (E)-8-tetradecenal that is active from the sensorystandpoint. The perfume or flavor composition is preferably a citruscomposition, the term citrus encompassing, in particular, bitter orange,lime, grapefruit, mandarin, clementine, lemon, cedral lemon, orange andkumquat.

Compositions according to the invention that contain a proportion of0.001 to 1% (m/m), preferably 0.001 to 0.1% (m/m) (Z)-8-tetradecenal,based on the total mass of the composition, are particularly preferred.Surprisingly, a proportion of only 0.001% (m/m) (Z)-8-tetradecenal is,specifically, already sufficient to make a conventional orange flavorfresher, juicier, more typical and more harmonious. Accordingly, in theuse according to the invention and the methods according to theinvention, the said proportions of (Z)-8-tetradecenal are advantageouslyset.

Finally, the present invention also relates to an article, for example(a) a personal hygiene product, a cleaning agent or another product notintended for consumption or (b) a food (including drinks suitable forconsumption), which contains a proportion of 0.0001 to 1% (m/m),preferably 0.01 to 0.1% (m/m) of a perfume or flavor compositionaccording to the invention, based on the total mass of the article.

Such an article preferably contains a proportion of 1 ppb to 100 ppm(Z)-8-tetradecenal, based on the total mass of the article.

The invention will be explained in more detail below on the basis ofexamples.

EXAMPLE 1 Determination of the Odor Threshold Values of (Z)-8- and(E)-8-tetradecenal and of Comparison Substances

The odor threshold values in water were determined in the conventionalmanner for (Z)-8- and (E)-8-tetradecenal and for two comparisonsubstances. The results are summarised in Table 1:

TABLE 1 Substance Odor threshold value [ppb] 7-(Z)-tetradecenal 2.60 ppb8-(Z)-tetradecenal 0.009 ppb  8-(E)-tetradecenal 1.24 ppb9-(Z)-tetradecenal 1.44 ppb

It can be seen that (Z)-8-tetradecenal has an odor threshold value thatis approximately 2 orders of magnitude lower than that of thestructurally related substances (Z)-7-tetradecenal and(Z)-9-tetradecenal.

EXAMPLE 2 Descriptions of the Odors of (Z)-8- and (E)-8-tetradecenal

The substances (Z)-8- and (E)-8-tetradecenal according to the inventionwere tested by a panel of expert flavoring specialists in theconventional manner. The experts assessed the relevant odors on thebasis of the procedure in the article entitled “Organoleptic propertiesof aliphatic aldehydes”, Boelens, Mans H.; Van Gemert, Leo J.; Perfum.Flavor. (1987), 12(5), 31-7, 40, 43, which has already been cited, i.e.they quantified the odors of the particular substance on the basis of anassessment scale with rankings of 0-4. The rankings have the followingmeanings:

-   0: absent-   1: weak-   2: moderate-   3: strong-   4: very strong

The results of the investigation are summarised in Table 2.

8-(Z)-tetradecenal 8-(E)-tetradecenal Citrus-like 4 1-2 Fruity 1 0Flowery 2 0-1 Of orange peel 4 0 Of pith 4 1 Sweet 3 1-2 Fatty 1 4 Waxy1-2 4 Green-herby 0 1 Honey-like 2 0 (beeswax) Fresh, fizzy 4 0 Chemical0-1 2-3

EXAMPLE 3 Modification of a Conventional Flavor Composition (OrangeFlavor)

A conventional flavor composition (composition A) was compared with aflavor composition according to the invention (composition B). As can beseen from Table 4 below, composition B substantially corresponded tocomposition A, but, in contrast to composition A, composition Bcontained a proportion of 0.005% (m/m) (Z)-8-tetradecenal (based on thetotal mass of the composition), which was compensated for by a reductionin the proportion of orange oil.

TABLE 4 Compositions of compositions A and B Orange flavor composition AB Octanal  0.3%  0.3% Linalool  0.7%  0.7% Decanal  0.4%  0.4% Citral 0.1%  0.1% Dodecanal 0.07%  0.07% Citronellal 0.06%  0.06% Terpineol0.07%  0.07% Ethyl butyrate 0.15%  0.15% Octanol 0.05%  0.05%Acetaldehyde 0.08%  0.08% Mandarin oil 0.15%  0.15% Lemon oil  0.8% 0.8% Orange oil 97.07 97.065 8-(Z)-tetradecenal 0.005%

The flavor of the composition B according to the invention wasdistinctly fresher, juicier, fuller and more typical compared with theflavor of the conventional composition A.

EXAMPLE 4 Synthesis of (Z)-8-tetradecenal

The synthesis is shown diagrammatically in FIG. 1.

(Z)-8-tetradecenal (6) was prepared in four steps from cyclooctene (1):ozonolysis of cyclooctene (1) and working up in accordance with themethod of S. L. Schreiber et al, (see below) gave methyl 8-oxooctanoate(2), which was converted to (Z)-tetradecene methyl ester (4) by(Z)-selective Wittig reaction with n-Hexyltriphenylphosphonium bromide(3). After reduction of (4) with lithium alanate to give the alcohol (5)and oxidation with PDC, (Z)-8-tetradecenal (6) was obtained:

Methyl 8-oxooctanoate (2)

Methyl 8-oxooctanoate (2) was prepared analogously to the method of S.L. Schreiber, R. E. Claus, J. Regan, Tetrahedron Letters 1982, 38,3867-3870:

48 g cyclooctene (1) and 8.4 g sodium bicarbonate were ozonolysed in 48g methanol and 1 l dichloromethane at −78° C. for 5.5 h. 304 gtriethylamine was added slowly dropwise at −60 [lacuna] C and thereaction mixture was allowed to warm to room temperature in the courseof 1 h. The reaction mixture was washed with sodium thiosulphatesolution (10%, 200 ml), 2 N HCl (150 ml), NaOH (5%, 150 ml) and NaClsolution (saturated, 200 ml) and dried over sodium sulphate and thesolvent was distilled off. After distillation, methyl 8-oxooctanoate (2)was obtained.

Methyl (Z)-8-tetradecenoate (4)

Methyl (Z)-8-tetradecenoate (4) was synthesised analogously to themethod of J. Bestmann, W. Stransky, O. Vostrowsky, Chem. Ber. 1976, 109,1694-1700 and L. F. Tietze, Th. Eicher, Reaktionen und Synthesen,(Reactions and Syntheses) Georg Thieme Verlag Stuttgart, New York 1991,192:

82.5 g n-hexyl bromide and 131.2 g triphenylphosphine were boiled underreflux for 35 h in 500 ml toluene. The solvent was distilled off, theresidue was taken up in dichloromethane and 1 l diethyl ether was added.Crystallisation at −15° C. gave n-hexyltriphenylphosphonium bromide (3).

29.35 g 3 and 150 ml potassium bis-(trimethylsilyl)-amide were boiled in120 ml THF (abs.) for 1.5 h under blanketing gas. 12.91 g methyl8-oxooctanoate (2) in 20 ml THF was added dropwise at −78° C. and thereaction mixture was stirred for 2.5 h at −78° C. The reaction mixturewas allowed to warm to room temperature, poured onto 150 ml sulphuricacid (10%)/75 g ice and extracted twice with 150 ml pentane. The organicphase was washed with sodium bicarbonate solution and NaCl solution(saturated) and dried over sodium sulphate and the triphenylphosphineoxide was separated off by crystallisation at −20° C. Distillation undera high vacuum gave methyl (Z)-8-tetradecenoate (4) (Z/E ratio accordingto GC>97/3).

(Z)-8-Tetradecen-1-ol (5)

(Z)-8-tetradecen-1-ol (5) was prepared analogously to the method of K.Schwetlick et al., Organikum, (Organic Chemistry), 17. Ed. VEB Verlag,Berlin 1988, pp. 494-495:

0.95 g lithium aluminium hydride was suspended in 150 ml diethyl etherunder blanketing gas and 10 g methyl (Z)-8-tetradecenoate (4) was addeddropwise at 0° C. The reaction mixture was stirred for 0.5 h at 0° C.and for 5 h at room temperature. 1 ml water and 1 ml NaOH solution (15%)were added and the mixture was filtered through silica gel. The silicagel was washed with ether, the organic phase was dried over sodiumsulphate and the solvent was distilled off. (Z)-8-tetradecen-1-ol (5)was obtained.

(Z)-8-Tetradecenal (6)

(Z)-8-tetradecenal (6) was prepared analogously to the method of E. J.Corey, G. Schmidt, Tetrahedron Letters 1979, 399-402:

15.8 g pyridinium dichromate in 300 ml dichloromethane were initiallyintroduced under blanketing gas and 5.93 g (Z)-8-tetradecen-1-ol (5) in50 ml dichloromethane was added, with stirring. The reaction mixture wasstirred for 15 h at room temperature and filtered through silica gel.Distillation under a high vacuum gave (Z)-8-tetradecenal (6).

¹H-NMR (300 MHz, CDCl₃): δ=0.89(t, J=7.0 Hz, 3H), 1.23-1.40 (m, 12H),1.63 (quint, J=7.5 Hz, 2H), 1.95-2.05 (m, 4H), 2.42 (dt, J=1.8, 7.5 Hz,2H), 5.35 (m_(c), 2H), 9.77 (t, J=1.38 Hz, 1H). ¹³C-NMR (75 MHz, CDCl₃):δ=14.09, 22.08, 22.61, 27.11, 27.21, 29.00, 29.09, 29.46, 29.53, 31.55,43.90, 129.6, 130.1, 202.8.

EXAMPLE 5 Synthesis of (E)-8-tetradecenal

The synthesis is shown diagrammatically in FIG. 2.

(E)-8-tetradecenal (10) was rendered accessible from (Z)-8-tetradecenal(6) in four steps by inversion of the double bond configuration:protection of the aldehyde functional group as dioxolane (7),epoxidation with m-chloroperbenzoic acid to give the oxirane (8),nucleophilic epoxide opening with inversion of the original double bondgeometry in accordance with the method of Vedejs to give the (E)-Alkene(9) and acid-catalysed deprotection of the acetal to give the targetcompound (E)-8-tetradecenal (10).

2-[(Z)-Tridec-7-enyl]-1,3-dioxolane (7)

2-[(Z)-tridec-7-enyl]-1,3-dioxolane (7) was prepared analogously to themethod of K. Schwetlick et al., Organikum, (Organic Chemistry) 17. Ed.VEB Verlag, Berlin 1988, 398:

5.6 g (Z)-8-tetradecenal (6), 2.0 g ethylene glycol and 20 mgp-toluenesulphonic acid in 150 ml toluene were boiled in a waterseparator for 3 h. The reaction mixture was washed with sodiumbisulphate solution and dried over sodium sulphate and the solvent wasdistilled off. Chromatography on silica gel gave2-[(Z)-tridec-7-enyl]-1,3-dioxolane (7).

2-[(7R,8S/7S,8R)-Epoxy-tridecanyl]-1,3-dioxolane (8)

Epoxidation with MCPBA in general: D. Swern, Organic Peroxides, Vol. 2,Wiley-Interscience, Interscience, New York 1971, 355-533.

3.75 g 2-[(Z)-tridec-7-enyl]-1,3-dioxolane (7) were initially introducedinto 50 ml dichloromethane and 5.44 g m-chloroperbenzoic acid (70%) wasadded in portions at 0° C. The reaction mixture was stirred for 3 h at0° C., diluted with 50 ml dichloromethane and washed with sodiumcarbonate solution (10%, 2×30 ml) and NaCl solution (saturated, 30 ml).The reaction mixture was dried over sodium sulphate and the solventdistilled off. 2-[(7R,8S/7S,8R)-epoxy-tridecanyl]-1,3-dioxalane (8) wasobtained.

2-[(E)Tridec-7-enyl]-1,3-dioxolane (9)

2-[(E)tridec-7-enyl]-1,3-dioxolane (9) was prepared analogously to themethod of E. Vedejs, P. L. Fuchs, J. Am. Chem. Soc 1973, 95, 822-825:

Lithium diphenylphosphide, ≈0.9 M in THF: 11.0 g chlordiphenylphosphinewere added dropwise under blanketing gas to 0.76 g lithium wire in 50 mldry THF. The reaction mixture was stirred for one day at roomtemperature.

2-[(E)Tridec-7-enyl]-1,3-dioxolane (9): 13.3 ml lithiumdiphenylphosphide (≈0.9 M in THF) were initially introduced into 30 mlTHF (abs.) and 2.70 g 2-[(7R,8S/7S,8R)-epoxy-tridecany]-1,3dioxalane (8)in 10 ml THF were added dropwise at room temperature. The reactionmixture was stirred for 2.5 h, 0.94 ml methyl iodide was added and thereaction mixture was stirred for 1 h. The reaction mixture was quenchedfor 30 min with 20 ml water and extracted with 500 ml diethyl ether. Theextract was washed with NaCl solution (saturated) and dried over sodiumsulphate and the solvent was distilled off. Triphenylphosphine oxide wasseparated off by crystallisation with pentane at −18° C. Distillationunder a high vacuum gave 2-[(E)tridec-7-enyl]-1,3-dioxolane (9).

(E)-8-Tetradecenal (10)

Deprotection of an ethlene (sic) glycol acetal by acid hydrolysis inaccordance with the method of J. Kocienski, Protecting Groups, GeorgThieme Verlag Stuttgart, New York 1994, 157-163:

0.89 g 2-[(E)tridec-7-enyl]-1,3-dioxolane (9), 30 mg p-toluenesulphonicacid and 25 ml of water were boiled in 75 ml methanol for 72 h underreflux under blanketing gas (86% conversion). The reaction mixture wasextracted twice with 200 ml diethyl ether, washed with 30 ml sodiumbicarbonate solution and dried over sodium sulphate and the solvent wasdistilled off under vacuum. Flash chromatography on silica gel gave(E)-8-tetradecenal (10) (E/Z ratio according to GC>97/3).

¹H-NMR (300 MHz, CDCl₃): δ=0,88 (t, J=6.9 Hz, 3H), 1.23-1.40 (m, 12H),1.63 (quint, J=7.2 Hz, 2H), 1.93-2.03 (m, 4H), 2.42 (dt, J=1.8, 7.3 Hz,2H), 5.35 (m_(c), 2H), 9.79 (t, J=1.8 Hz, 1H). ¹³C-NMR (75 MHz, CDCl₃):δ=14.09, 22.07, 22.57, 28.83, 29.04, 29.35, 29.39, 31.42, 32.49, 32.59,43.91, 130.0, 130.6, 202.8.

1. An article comprising a perfume or flavoring agent, wherein saidperfume or flavoring agent comprises (Z)-8-tetradecenal,(E)-8-tetradecenal, or a mixture thereof.
 2. A method for imparting acitrus perfume or citrus flavor to, or intensifying the citrus perfumeor citrus flavor of, a base composition comprising constituents, saidmethod comprising mixing said constituents with an amount of(Z)-8-tetradecenal, (E)-8-tetradecenal, or a mixture thereof, thatimparts a citrus scent or citrus flavor to said base composition orintensifies the citrus odor or citrus flavor of said base composition.3. A method for modifying a perfume or flavor composition, said methodcomprising adding to said composition (Z)-8-tetradecenal,(E)-8-tetradecenal, or a mixture thereof, in an amount that modifies theperfume or flavor of said composition by adding or intensifying citrusnotes.
 4. A perfume or flavor composition comprising an amount of(Z)-8-tetradecenal, (E)-8-tetradecenal, or a mixture thereof, thatimparts or intensifies a citrus scent or citrus flavor.
 5. The perfumeor flavor composition according to claim 4, wherein said compositioncomprises about 0.001 to about 1% (m/m) (Z)-8-tetradecenal, based uponthe total mass of the composition.
 6. The perfume or flavor compositionaccording to claim 5, wherein said composition comprises 0.001 to 0.1%(m/m) (Z)-8-tetradecenal, based upon the total mass of the composition.7. An article comprising about 0.0001 to about 1% (m/m) of a perfume orflavor composition according to claim 4, based upon the total mass ofsaid article.
 8. The article of claim 7, wherein said article comprises0.001 to 0.1% (m/m), based upon the total mass of the article, of saidcomposition.
 9. An article comprising about 1 ppb to about 100 ppm(Z)-8-tetradecenal, based upon the total mass of said article, whereinsaid article has a citrus odor or citrus flavor.
 10. The article ofclaim 1, wherein the article is a personal hygiene product, a cleaningagent, or another product not intended for consumption.
 11. The articleof claim 1, wherein the article is food or a drink.